Page 1 of 2
home made slide check valve for piloting
Posted: Sun Aug 17, 2008 9:04 am
by trollhameran
After reading a thread about using a slide check valve for a pilot, I decided to have a go at building my own from scratch.
Its not completely finished, but so far it has turned out very well. It seals perfectly, and the air vents out very quickly.
The only problem I want to fix is, at the moment the slide doesn't move back into position as easily as I would like.
It is perfect for a single shot gun, but I am planning on using it for an auto loading rifle so it needs to close as fast as it opens, for efficiency. so I am going to experiment with springs to try and get it to close quickly.
The final thing I am going to do to it is weld a piece of metal in the shape of a trigger onto the slide, so that the slide can be operated by your finger, like a trigger from a real gun.

[/img]

Posted: Sun Aug 17, 2008 9:47 am
by daberno123
It definitely has potential, but I can see how you have to pull pretty hard to open it.
How many holes are there and how big are they?
Posted: Sun Aug 17, 2008 9:50 am
by Gippeto
Excellent work!! You got that together very quickly.
Works great too.
Did you use four 4mm holes as planned?
What size is the copper tube you are using?
Posted: Sun Aug 17, 2008 10:00 am
by trollhameran
Thanks
Once it has a proper trigger on it, it wont be any harder than an air rifle trigger to pull, it was quite hard to do it in the video, mainly because I put to much grease on the inside and it went all over everything
Yeah there are four 4mm holes in a single line around the pipe.
Its 15mm pipe,and the slide is made of 22mm as that fits nicely over the 15mm when the o rings are in place.
I will take a picture of what it looks like underneath the slide in a minute or two
Posted: Sun Aug 17, 2008 10:08 am
by trollhameran
[img][img]
http://i256.photobucket.com/albums/hh17 ... 008753.jpg[/img][/img]
Thats the seals and what not, There are four of those holes positioned around the pipe, I decided it would be easier to have the slide move along the o rings rather than fixing the o rings to the slide and having them move along the pipe.
Posted: Sun Aug 17, 2008 10:33 am
by Gippeto
Very simple.
The blow gun I use on my copper gun has a horrendous trigger pull at 400psi.
I think something like this is going to be a big improvement.
Ragnarok uses/used a slide valve as a trigger on HEAL.
Maybe he will chime in and tell us what the trigger pull is like?
Posted: Sun Aug 17, 2008 10:54 am
by PVC Arsenal 17
That looks great! Didn't seem to take you long to make. It's a wonder we don't see slide checks used more often.
Posted: Sun Aug 17, 2008 10:59 am
by trollhameran
I would definitely recommend it instead of a blowgun, it is so easy to make and it can be build straight onto the end of your pipe, so you dont need to buy any fixings to get the pipe down to the right size to fix on to the blowgun.
Heres a video and a picture of a gun I just put it onto to test it, its not very powerful....at the moment but i plan to reduce the pilot size massively and increase the chamber size and barrel length.
Also I know the barrel isn't straight, I was playing around with the falling block design again and its just something I threw together out of scrap.

Posted: Sun Aug 17, 2008 5:17 pm
by psycix
Nicely made!
The only problem I want to fix is, at the moment the slide doesn't move back into position as easily as I would like.
When sliding it back on, its disangled and needs to be pulled straight before it can get back on the o-ring right?
You could add one more o-ring behind the hole so it remains resting on 2 o-rings or more at all times and doesnt get disangled.
Posted: Sun Aug 17, 2008 9:41 pm
by POLAND_SPUD
AFAIK these things are hard to open as the pressure increases.. I don't remember who told me so maybe it was ragnarok... well who cares they are the cheapest 3 way valves available
@trollhamermann - nice job it looks quite good I have one question is exactly like an off the shelf slide-check valve? In a way that it blocks one side when the other is vented or does it only vent the whole system?
Posted: Sun Aug 17, 2008 10:08 pm
by grumpy
I use a slide valve on a remote line for my paintball markers and it operates easily with 850 psi. a little oil on the orings and the inside of the sleave will help.
Posted: Sun Aug 17, 2008 11:40 pm
by Gippeto
Thank you Grumpy, I'm convinced.
Another lunch time project.

Posted: Mon Aug 18, 2008 12:58 am
by trollhameran
psycix: yeah I did think about putting another o ring in to help it stay straight, I will try and find one and put it in today.
POLAND_SPUD: It only vents the whole system, which is what I wanted, I think it could be modded to work exactly the same as an off the shelf valve though, It would need four o rings though, I think.
Im going to make a trigger for it, and maybe put another o ring in today, so ill post it up when its done.

Posted: Mon Aug 18, 2008 10:41 am
by Brian the brain
You will need to block the center pipe in order to have it work as a three way...
Posted: Mon Aug 18, 2008 11:00 am
by starman
Sweet little item Troll...just got kicked into the bookmarks.